Cosmetic composition having pearlescent effect by means of lamellar liquid crystal sheet containing ultra-long-chain fatty acid

Abstract

A cosmetic composition having a pearlescent effect, according to one aspect, provides a pearlescent effect without a pearlescent pigment so as to improve aesthetics, can be used in various formulations such as low-viscosity skin formulations, can exhibit structural colors, and has excellent long-term formulation stability.

Description

Cosmetic composition having a pearlescent effect using lamellar liquid crystal sheets containing long-chain fatty acids

[0001] The present invention relates to a cosmetic composition having a pearlescent effect using a lamellar liquid crystal sheet containing a long-chain fatty acid.

[0002] Between the stratum corneum of the skin, polar lipids secreted from the epidermis and non-polar lipids produced by the sebaceous glands form a combined membrane. Including these, the moisture barrier between the stratum corneum and the granular layer, and the basal cell membrane below the basal layer, the skin barrier is collectively referred to as the skin barrier. Lipid components formed in the stratum corneum include ceramide, cholesterol, and fatty acids.

[0003] Meanwhile, pearl gloss technology is an important technology for enhancing the aesthetics and luxury of cosmetics. In the case of pearl-containing cosmetics used in existing products, pearl pigments coated with sheet-shaped mica or titanium oxide are applied. These pearl pigments produce a pearl effect visually as the plate-shaped particles reflect light multiple times. However, cosmetics containing such pearl pigments can only be used in solid formulations such as lipsticks, foundations, and eyeshadows, which enhance the human appearance, and there is a problem of causing skin irritation.

[0004] The inventors of the present invention have endeavored to develop a cosmetic composition having excellent formulation stability and a pearlescent effect that does not irritate the skin, by including ceramide, cholesterol, and fatty acids, which are lipids found in the skin. Accordingly, the present invention was completed by confirming the excellent pearlescent effect and formulation stability of the cosmetic composition.

[0005] One aspect provides a cosmetic composition having a pearly feel, comprising a long-chain fatty acid, a ceramide, cholesterol, a nonionic surfactant, and a polyol.

[0006] Another aspect provides a method for preparing a cosmetic composition having a pearlescent effect comprising an extra-long chain fatty acid, ceramide, cholesterol, a nonionic surfactant, and a polyol.

[0007] Another aspect provides a topical skin composition having a pearlescent finish comprising an extra-long chain fatty acid, ceramide, cholesterol, a nonionic surfactant, and a polyol.

[0008] Other objects and advantages of this application will become more apparent from the following detailed description, together with the appended claims and drawings. Anything not described in this specification is omitted, as it can be sufficiently recognized and inferred by those skilled in the art of this application or a similar art field.

[0009] Each description and embodiment disclosed in this application may also be applied to each other description and embodiment. That is, all combinations of the various elements disclosed in this application fall within the scope of this application. Furthermore, the scope of this application is not limited by the specific descriptions described below.

[0010] One aspect provides a cosmetic composition having a pearly feel, comprising a long-chain fatty acid, a ceramide, cholesterol, a nonionic surfactant, and a polyol.

[0011] The above cosmetic composition can form a multilayer lamellar liquid crystal sheet.

[0012] In this specification, the term “lamellar liquid crystal sheet” refers to a liquid crystal structure in which the intercellular lipids and surfactants of skin keratinocytes form a lamellar structure and form a plate-like structure.

[0013] Cosmetic compositions with a lamellar liquid crystal structure are produced due to various variables such as the type of emulsion, the type and concentration of the ingredients included therein, and the shear rate and temperature of the manufacturing process.

[0014] The above lamellar liquid crystal sheet can reflect light in a low-viscosity formulation to create a pearlescent effect depending on the viewing angle and light source. Additionally, natural moisturizing factors can be contained between the water layers of the lamellar liquid crystal sheet, thereby providing moisture to the skin.

[0015] The above cosmetic composition can exhibit a multilayer structural color.

[0016] In this specification, the term “structural color” refers to a color produced by the microstructure rather than the chemical composition of a substance, appearing as optical phenomena such as scattering, interference, refraction, and reflection as light of a specific wavelength interacts with the microstructure, even without the addition of pigments. Representative examples include peacock feathers and butterfly wings, and structural color may appear in the cosmetic composition due to the lamellar liquid crystal sheet.

[0017] In this specification, the term “very long chain fatty acid (VLCFA)” means a carboxylic acid having an aliphatic chain having 22 to 30 carbon atoms.

[0018] The above-mentioned very long-chain fatty acid may be a saturated or unsaturated fatty acid, may be a straight chain or a branched chain, and may be one or more selected from the group consisting of, for example, behenic acid (C22:0), lignoceric acid (C24:0), tetracosenoic acid (C24:1), cerotic acid (C26:0), hexacosenic acid (C26:1), montanic acid (C28:0), octacosenoic acid (C28:1), and melissic acid (C30:0). In one embodiment, the above-mentioned very long-chain fatty acid may be behenic acid.

[0019] The above-mentioned very long-chain fatty acid may be included in an amount of 0.01 to 5 weight% based on the total weight of the composition. For example, it may be included in an amount of 0.01 to 5 weight%, 0.01 to 4 weight%, 0.01 to 3 weight%, 0.01 to 2 weight%, 0.01 to 1 weight%, 0.05 to 5 weight%, 0.05 to 4 weight%, 0.05 to 3 weight%, 0.05 to 2 weight%, 0.05 to 1 weight%, 0.1 to 5 weight%, 0.1 to 4 weight%, 0.1 to 3 weight%, 0.1 to 2 weight%, or 0.1 to 1 weight%. If the amount falls outside the above range, it may be difficult to form a pearlescent effect, and precipitation may occur, which may cause problems with formulation stability.

[0020] According to one specific example, a formulation comprising a very long-chain fatty acid, a ceramide, cholesterol, a nonionic surfactant, and a polyol has superior long-term formulation stability compared to a cosmetic composition that does not include such a composition.

[0021] The above cosmetic composition may additionally contain a long-chain fatty acid.

[0022] In this specification, the term “long chain fatty acid (LCFA)” means a carboxylic acid having an aliphatic chain of 13 to 21 carbon atoms.

[0023] The long-chain fatty acid may be a saturated or unsaturated fatty acid, may be straight or branched, and may be one or more selected from the group consisting of, for example, myristic acid, palmitic acid, oleic acid, linoleic acid, stearic acid, and arachidic acid. In one embodiment, the long-chain fatty acid may be stearic acid.

[0024] The above cosmetic composition may contain a long-chain fatty acid to exhibit structural color.

[0025] The long-chain fatty acid may be included in an amount of 0.01 to 5 wt% based on the total weight of the composition. For example, it may be included in an amount of 0.01 to 5 wt%, 0.01 to 4 wt%, 0.01 to 3 wt%, 0.01 to 2 wt%, 0.01 to 1 wt%, 0.05 to 5 wt%, 0.05 to 4 wt%, 0.05 to 3 wt%, 0.05 to 2 wt%, 0.05 to 1 wt%, 0.1 to 5 wt%, 0.1 to 4 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, or 0.1 to 1 wt%. If it is out of the above range, it may be difficult to form a pearlescent finish and precipitation may occur, which may cause problems with the stability of the formulation.

[0026] The above ultra-long-chain fatty acids and long-chain fatty acids may be included in an amount of 0.01 to 5 wt% based on the total weight of the composition. For example, they may be included in an amount of 0.01 to 5 wt%, 0.01 to 4 wt%, 0.01 to 3 wt%, 0.01 to 2 wt%, 0.01 to 1 wt%, 0.05 to 5 wt%, 0.05 to 4 wt%, 0.05 to 3 wt%, 0.05 to 2 wt%, 0.05 to 1 wt%, 0.1 to 5 wt%, 0.1 to 4 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, or 0.1 to 1 wt%. If the amount is outside the above range, it may be difficult to form a pearlescent finish and precipitation may occur, which may cause problems with the stability of the formulation.

[0027] In this specification, the term “Ceramide” refers to N-acylsphingosine, an intercellular lipid that fills the spaces between keratinocytes and is an essential component for the structural formation or function of the stratum corneum. When the above-mentioned ceramide is used in a cosmetic composition, the skin moisturizing effect can be enhanced and the skin barrier improvement effect can be increased. However, since the above-mentioned ceramide is a poorly soluble substance, there are many limitations to its application in cosmetics, and in cosmetic compositions containing ceramide, phase separation, precipitation, and gelling frequently occur during the formulation process.

[0028] The above ceramide may include not only natural ceramide but also substances that act as a skin barrier similar to natural ceramide, and the above ceramide may be one or more selected from the group consisting of, for example, ceramide EOP, ceramide NS, ceramide NP, ceramide AS, ceramide AP, ceramide EOS, and ceramide NDS.

[0029] In one embodiment, the ceramide may be included in an amount of 0.001 to 5 weight% based on the total weight of the composition. For example, it may be included in an amount of 0.001 to 5 weight%, 0.001 to 4 weight%, 0.001 to 3 weight%, 0.001 to 2 weight%, 0.001 to 1 weight%, 0.01 to 5 weight%, 0.01 to 4 weight%, 0.01 to 3 weight%, 0.01 to 2 weight%, or 0.01 to 1 weight%. If the amount falls outside the 5 weight% range, problems such as difficulty in dissolution and precipitation may occur.

[0030] In one specific example, the ceramide may be a ceramide NP.

[0031] Cholesterol, as an intercellular lipid component, strengthens the hydrophobic role of the liquid crystal structure and prevents the swelling of lamellar liquid crystals. Like ceramide, it also functions as a skin barrier and is a poorly soluble substance.

[0032] In one specific example, the cholesterol may be present in an amount of 0.05 to 5 wt% based on the total weight of the composition. For example, the cholesterol may be present in an amount of 0.05 to 5 wt%, 0.05 to 4 wt%, 0.05 to 3 wt%, 0.05 to 2 wt%, 0.05 to 1 wt%, 0.1 to 5 wt%, 0.1 to 4 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, or 0.1 to 1 wt%. If the amount is outside the above range, precipitation may occur, resulting in formulation problems.

[0033] The term "nonionic surfactant" as used herein refers to a surfactant that does not dissociate into ions in water. The nonionic surfactant may be a mixture of two surfactants having different HLB (Hydrophile-Lipophile Balance) values. The cosmetic composition can stably form a lamellar liquid crystal sheet by using nonionic surfactants having different HLB values.

[0034] In one specific embodiment, the nonionic surfactant may be included in an amount of 0.01 to 20 wt% based on the total weight of the composition. For example, the nonionic surfactant may be included in an amount of 0.01 to 20 wt%, 0.01 to 10 wt%, 0.01 to 5 wt%, 0.01 to 3 wt%, 0.01 to 1 wt%, 0.05 to 10 wt%, 0.05 to 5 wt%, 0.05 to 3 wt%, 0.05 to 1 wt%, 0.1 to 10 wt%, 0.1 to 5 wt%, 0.1 to 3 wt%, 0.1 to 1 wt%, 0.5 to 10 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, or 0.1 to 1 wt%.

[0035] In one specific example, the nonionic surfactant may be a mixture of hydrogenated lecithin and polyglyceryl fatty ester (PGFE) surfactants.

[0036] In the case of hydrogenated lecithin, it refers to a substance in which hydrogen is added to lecithin, which is a diglyceride mixture, for stability. This substance is an amphiphilic substance containing both hydrophilic and lipophilic properties, and has the characteristic of forming a double molecular film when dispersed in water, which plays a role in facilitating application of a lamellar liquid crystal phase. In one specific example, the hydrogenated lecithin may be included in an amount of 0.1 to 10 wt% based on the total weight of the composition. For example, it may be included in an amount of 0.1 to 10 wt%, 0.1 to 5 wt%, 0.1 to 3 wt%, 0.1 to 1 wt%, 0.5 to 10 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, or 0.1 to 0.5 wt%. If it is out of the above range, it is difficult to form a pearlescent feel, and crystallization of particles may occur.

[0037] The above polyglyceryl fatty acid ester surfactant may be at least one selected from the group consisting of polyglyceryl-10 caprate, polyglyceryl-10 laurate, polyglyceryl-10 myristate, polyglyceryl-10 trilaurate, polyglyceryl-10 oleate, polyglyceryl-10 dioleate, polyglyceryl-10 stearate, polyglyceryl-10 isostearate, polyglyceryl-10 pentastearate, polyglyceryl-10 behenate, polyglyceryl-10 decaliterate, and polyglyceryl-10 behenate / elcosadroate.

[0038] In one specific example, the polyglyceryl fatty acid ester surfactant may be included in an amount of 0.01 to 10 wt% based on the total weight of the composition. For example, it may be included in an amount of 0.01 to 10 wt%, 0.01 to 5 wt%, 0.01 to 3 wt%, 0.01 to 1 wt%, 0.05 to 10 wt%, 0.05 to 5 wt%, 0.05 to 3 wt%, 0.05 to 1 wt%, 0.1 to 10 wt%, 0.1 to 5 wt%, 0.1 to 3 wt%, 0.1 to 1 wt%, 0.5 to 10 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, or 0.1 to 1 wt%. If it is out of the above range, it is difficult to form a pearlescent effect, and crystallization of particles may occur.

[0039] To maintain structural stability within cosmetics, polyethylene glycol (PEG) surfactants are widely used in many formulations. However, PEG can produce ethylene oxide and 1,4-dioxane as byproducts during the manufacturing process. These substances have toxic effects and can affect skin barrier function.

[0040] More specifically, the nonionic surfactant may be hydrogenated lecithin and polyglyceryl-10 myristate. According to one embodiment, using hydrogenated lecithin with an HLB value of about 8 and polyglyceryl-10 myristate with an HLB value of about 16, it was confirmed that a lamellar liquid crystal sheet was stably formed to exhibit a pearlescent effect and that no separation between the oil phase and the aqueous phase occurred even after a period of time.

[0041] The term “Polyol” refers to an aliphatic compound having two or more hydroxyl groups (-OH) that is interchangeable with “polyhydric alcohol.” The polyol may be, for example, one or more selected from the group consisting of butylene glycol, propylene glycol, dipropylene glycol, isopropylene glycol, ethoxydiglycol, triethylene glycol, hexylene glycol, pentylene glycol, and polyethylene glycol. The polyol is not limited thereto, but it is suitable for having an IOB (Inorganic Organic Balance) value of 3.5 or less, which is an indicator of the polarity of a water-soluble solvent.

[0042] The above polyol may be included in an amount of 5 to 50 weight% based on the total weight of the composition. For example, it may be included in an amount of 5 to 50 weight%, 5 to 40 weight%, 5 to 30 weight%, 5 to 20 weight%, 10 to 50 weight%, 10 to 40 weight%, 10 to 30 weight%, or 10 to 20 weight%. If the amount falls outside the above range, problems with the stability of the formulation may occur due to changes in polarity within the formulation.

[0043] The above cosmetic composition may additionally contain purified water.

[0044] The above cosmetic composition may comprise an oil phase comprising an ultra-long chain fatty acid, ceramide, cholesterol, and a nonionic surfactant; and an aqueous phase comprising purified water and a polyol.

[0045] The above polyol may also be included in the oil phase.

[0046] The above cosmetic composition may be an oil-in-water (O / W) cosmetic composition.

[0047] The composition according to one aspect comprises an aqueous phase comprising purified water and a polyol, and an oil phase comprising a very long-chain fatty acid, ceramide, cholesterol, and a nonionic surfactant. The lipid phase is composed of lamellar liquid crystal sheets, and its light reflectance can vary depending on the viewing angle and light source, forming a pearlescent effect, and it affects skin barrier restoration and moisturizing.

[0048] Cosmetic compositions in the form of emulsions, which are oil-in-water types, use emulsifiers to form stable formulations of water and oil phases that do not mix with each other. In one embodiment, nonionic surfactants, hydrogenated lecithin and polyglyceryl-10 myristate, were used, and a very long-chain fatty acid was used to stably form lamellar liquid crystal sheets, resulting in a pearlescent effect and no separation of layers between the oil and water phases even after time elapsed.

[0049] The above cosmetic composition may be in one formulation selected from the group consisting of essence, serum, skin, mist, spray, lotion, cream, gel, and pack, but is not limited thereto as long as it is a low viscosity formulation that can be applied topically or through the skin.

[0050] The above cosmetic composition may further include, but is not limited to, additional ingredients commonly added to cosmetics, such as oils, emulsifiers, dispersants, fragrances, preservatives, sweeteners, neutralizers, vitamins, metal ion sequestrants, functional additives, or mixtures thereof.

[0051] Another aspect provides a method for preparing a cosmetic composition having a pearlescent effect, comprising the following steps:

[0052] (1) A step of preparing an oil phase by mixing a very long-chain fatty acid, ceramide, cholesterol, and a nonionic surfactant;

[0053] (2) A step of preparing a water phase by mixing polyol into purified water; and

[0054] (3) A step of mixing by introducing an oil phase into the above-mentioned water phase.

[0055] The same parts as described in the above cosmetic composition also apply to the above method.

[0056] The above step (1) can be performed at a temperature of 80°C to 110°C. For example, it can be performed at a temperature of 80°C to 110°C, 80°C to 100°C, 90°C to 110°C, or 90°C to 100°C. If the temperature is below the above range, the compound corresponding to the lipid portion may be difficult to dissolve, and if the temperature is above the above range, browning of ceramide or lecithin may occur. In addition, the above step (1) can be stirred at a condition of 500 to 1000 rpm. For example, stirring can be performed under conditions of 500 to 1000 rpm, 500 to 900 rpm, 500 to 800 rpm, 500 to 700 rpm, 500 to 600 rpm, 600 to 1000 rpm, 600 to 900 rpm, 600 to 800 rpm, or 600 to 700 rpm.

[0057] The above step (2) can be performed at a temperature of 70°C to 90°C. For example, it can be performed at a temperature of 70°C to 90°C, 70°C to 80°C, 75°C to 90°C, or 75°C to 85°C. In addition, the above step (2) can be stirred at a speed of 100 to 500 rpm. For example, it can be stirred at a speed of 100 to 500 rpm, 100 to 350 rpm, 150 to 250 rpm, or 150 to 200 rpm.

[0058] The above step (3) can be stirred at a speed of 1500 to 3000 rpm. For example, stirring can be performed at a speed of 1500 to 3000 rpm, 1500 to 2500 rpm, or 2000 to 2500 rpm.

[0059] The above method may further include a step of rapidly cooling the mixture to vacuum degassing.

[0060] The rapid cooling may mean cooling to 40°C to 60°C, 40°C to 50°C, 30°C to 60°C, or 30°C to 50°C within a short period of time. The short period of time may mean 5 to 15 minutes, 5 to 10 minutes, or 10 to 15 minutes.

[0061] Another aspect provides a topical skin composition having a pearlescent finish comprising an extra-long chain fatty acid, ceramide, cholesterol, a nonionic surfactant, and a polyol.

[0062] The same parts as those described in the above cosmetic composition also apply equally to the above external skin preparation.

[0063] In this specification, the term “topical skin preparation” is a concept that generally encompasses all compositions used externally, and may refer to a wide range of products that can be applied to various pharmaceuticals or quasi-pharmaceuticals, such as cosmetic compositions including various cosmetics such as basic cosmetics, makeup cosmetics, hair cosmetics, and shaving cosmetics, or ointments.

[0064] The formulation of the above-mentioned external skin composition may take an appropriate form depending on the intended use and the properties of the external composition, and specifically may be an aqueous solution type, a solubilization type, an emulsion type, a fluid type, a gel type, a paste type, an ointment type, an aerosol type, a water-oil two-layer type, or a water-oil-powder three-layer type, and the formulation and form of the external agent of the present invention are not limited by the above-mentioned formulation.

[0065] A cosmetic composition having a pearlescent effect according to the daily aspect provides a pearlescent effect without pearl pigment to improve the appearance, can be used in various formulations such as low-viscosity skin formulations, and has excellent long-term formulation stability.

[0066] Figure 1 shows the appearance of Examples 1 to 4 and Comparative Example 1 one week after preparation.

[0067] Figure 2 shows the appearance of Examples 1 to 4 and Comparative Example 1 one month after preparation.

[0068] Figure 3 shows the appearance of Example 5 one month after manufacturing.

[0069] Figure 4 shows the appearance of Example 6 one month after manufacturing.

[0070] Figure 5 shows the appearance of Example 7 one month after manufacturing.

[0071] Figure 6 shows the appearance of Comparative Example 2 one month after manufacturing.

[0072] Figure 7 shows the appearance of Comparative Example 3 one month after manufacturing.

[0073] Figure 8 shows the appearance of Comparative Example 4 one month after manufacturing.

[0074] Figure 9 is a photograph of the Cryo-Tem of Example 3. (Lamellar liquid crystal sheet)

[0075] Hereinafter, preferred examples are presented to aid in understanding the present invention. However, the following examples are provided solely to facilitate a better understanding of the present invention, and the scope of the present invention is not limited by the following examples.

[0076] Examples 1 to 7 and Comparative Examples 1 to 4. Preparation of cosmetic compositions having a pearlescent effect

[0077] A cosmetic composition having a pearlescent effect was prepared. Example 1 was prepared using only behenic acid, an extra-long chain fatty acid, and Comparative Example 1 was prepared using only stearic acid, a long chain fatty acid. Examples 2 to 4 were prepared using a mixture of behenic acid and stearic acid. Example 5 was prepared using a mixture of behenic acid and palmitic acid, and Comparative Example 2 was prepared using only palmitic acid. Example 6 was prepared using a mixture of behenic acid and myristic acid, and Comparative Example 3 was prepared using only myristic acid. Example 7 was prepared using a mixture of behenic acid, stearic acid, palmitic acid, and myristic acid, and Comparative Example 4 was prepared using a mixture of stearic acid, palmitic acid, and myristic acid.

[0078] In the above cosmetic composition, the components and content of the aqueous phase and the oil phase, respectively, are as shown in Tables 1 to 3 below.

[0079] Ingredients Example 1 (Weight%) Example 2 (Weight%) Example 3 (Weight%) Example 4 (Weight%) Aqueous Phase Ampere Water To 100 To 100 To 100 To 100 1,3-Butylene Glycol 10101010 Oil Phase Butylene Glycol 10101010 Cholesterol 0.25 0.25 0.25 0.25 Ceramide NP 0.01 0.01 0.01 -Hydrogenated Lecithin 0.5 0.5 0.5 0.5 Polyglyceryl-10 Myristate 1111 Myristic Acid----Palmitic Acid----Stearic Acid-0.25 0.5 0.75 Behenic Acid 10.75 0.5 0.25 Total 100.00 100.00 100.00 100.00 100.00

[0080] Ingredients Example 5 (Weight%) Example 6 (Weight%) Example 7 (Weight%) Aqueous Phase Purified Agent Water To 100 To 100 To 100 1,3-Butylene Glycol 101010 Oil Phase Butipropylene Glycol 101010 Cholesterol 0.25 0.25 0.25 Ceramide NP 0.01 0.01 0.01 Hydrogenated Lecithin 0.5 0.5 0.5 Polyglyceryl-10 Myristate 111 Myristic Acid 0.5 0.167 Palmitic Acid 0.5 0.167 Stearic Acid 0.167 Behenic Acid 0.5 0.5 0.5 Total 100.00 100.00 100.00

[0081] Ingredient Comparison Example 1 (weight%) Comparison Example 2 (weight%) Comparison Example 3 (weight%) Comparison Example 4 (weight%) Water phase Unpurified water To 100 To 100 To 100 To 100 1,3-Butylene glycol 10 10 10 10 10 Oil phase Dipropylene glycol 10 10 10 10 Cholesterol 0.25 0.25 0.25 0.25 Ceramide NP-0.01 0.01 0.01 Hydrogenated lecithin 0.5 0.5 0.5 0.5 Polyglyceryl-10 myristate 1 1 1 Myristic acid--10.333 Palmitic acid-1-0.333 Stearic acid-1--0.333 Behenic acid----Total 100.00 100.00 100.00 100.00

[0082] Specifically, all of the oil phase components were mixed and stirred at 80 to 110°C and 500 to 1000 rpm to prepare the oil phase. All of the water phase components were mixed and stirred at 70 to 90°C and 100 to 500 rpm to prepare the water phase separately. Thereafter, the prepared oil phase was added to the water phase and stirred at 1500 to 3000 rpm using a homomixer. After the addition, the mixture was rapidly cooled to 40°C within 10 minutes and degassed using a vacuum pump to prepare an oil-in-water cosmetic composition (0 / W).

[0083] Experimental Example 1. Visual confirmation of structural color according to the combination of very long-chain fatty acids (behenic acid) and long-chain fatty acids (stearic acid)

[0084] In this experimental example, the effects of ultra-long-chain fatty acids (behenic acid) and long-chain fatty acids (stearic acid) on the structural color of cosmetic compositions were examined. To this end, the cosmetic compositions of Examples 1 to 4 and Comparative Example 1 were visually examined to determine whether a pearlescent effect was formed after one month.

[0085] Figure 1 shows the appearance of Examples 1 to 4 and Comparative Example 1 one week after preparation. They were arranged in the order of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1.

[0086] Figure 2 shows the appearance of Examples 1 to 4 and Comparative Example 1 one month after preparation. They were arranged in the order of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1.

[0087] As a result, as shown in Fig. 1, it was confirmed that the more stearic acid was contained, the closer the particle showed a color to a long wavelength. After one week of manufacture, it was confirmed that no layer separation phenomenon occurred between the water phase and the oil phase in Examples 1 to 4 and Comparative Example 4, and all showed a pearlescent appearance.

[0088] However, as shown in Fig. 2, one month after manufacture, no separation of layers between the water phase and the oil phase was observed in Examples 1 to 4, but in the case of Comparative Example 1, a separation of layers between the water phase and the oil phase was observed.

[0089] Experimental Example 2. Confirmation of formulation stability according to the presence or absence of very long-chain fatty acids (behenic acid).

[0090] In this experimental example, the effect of a very long-chain fatty acid (behenic acid) on the formulation stability of a cosmetic composition with a pearlescent finish was examined. To this end, the cosmetic compositions of Examples 5 to 7 and Comparative Examples 2 to 4 were visually examined to determine whether layer separation occurred between the aqueous and oil phases one month after preparation of the cosmetic compositions.

[0091] Figure 3 shows the appearance of Example 5 one month after manufacturing.

[0092] Figure 4 shows the appearance of Example 6 one month after manufacturing.

[0093] Figure 5 shows the appearance of Example 7 one month after manufacturing.

[0094] Figure 6 shows the appearance of Comparative Example 2 one month after manufacturing.

[0095] Figure 7 shows the appearance of Comparative Example 3 one month after manufacturing.

[0096] Figure 8 shows the appearance of Comparative Example 4 one month after manufacturing.

[0097] As a result, as shown in Figures 3 to 5, in the case of Examples 5 to 7 containing behenic acid, an ultra-long chain fatty acid, no layer separation between the aqueous phase and the oil phase was observed, whereas in the case of Comparative Examples 2 to 4, which do not contain behenic acid, an ultra-long chain fatty acid, it was confirmed that layer separation between the aqueous phase and the oil phase occurred.

[0098] The above experimental results indicate that formulation stability for a cosmetic composition having a pearlescent feel can be achieved by ultra-long-chain fatty acids.

[0099] Experimental Example 3. Structural Confirmation of Cosmetic Compositions

[0100] The structure of the cosmetic composition of Example 3 was confirmed through Cryo-TEM (low-temperature electron microscope, model name: Glacios, manufacturer: Thermofisher). Specifically, pretreatment was performed for 30 seconds without separate dilution using a pretreatment device (model name: Vitrobot Mark IV, manufacturer: FEI) under the conditions of glow discharge (plasma cleansing), hydrogen 7, oxygen 7, argon 7, blot time 3 seconds, blot force 3, 22 degrees Celsius, and 100% relative humidity. After that, the pretreated sample was freeze-dried and then observed.

[0101] Figure 9 is a photograph of the Cryo-Tem of Example 3. (Lamellar liquid crystal sheet)

[0102] As a result, it was confirmed that a lamellar liquid crystal sheet was formed, as shown in Fig. 9.

[0103] The foregoing description of the present invention is provided for illustrative purposes only. Those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A cosmetic composition having a pearly feel, comprising a long-chain fatty acid, ceramide, cholesterol, a nonionic surfactant, and a polyol.

2. A cosmetic composition according to claim 1, wherein the ultra-long-chain fatty acid has 22 to 30 carbon atoms.

3. A cosmetic composition according to claim 1, wherein the ultra-long-chain fatty acid is at least one selected from the group consisting of behenic acid (C22:0), lignoceric acid (C24:0), tetracosenoic acid (C24:1), cerotic acid (C26:0), hexacosenoic acid (C26:1), montanic acid (C28:0), octacosenoic acid (C28:1), and melistan (melissic acid (C30:0).

4. A cosmetic composition according to claim 1, wherein the cosmetic composition further comprises a long-chain fatty acid.

5. A cosmetic composition according to claim 4, wherein the long-chain fatty acid has 13 to 21 carbon atoms.

6. A cosmetic composition according to claim 4, wherein the long-chain fatty acid is at least one selected from the group consisting of myristic acid, palmitic acid, oleic acid, linoleic acid, stearic acid, and arachidic acid.

7. A cosmetic composition according to claim 1, wherein the cosmetic composition forms a sheet of lamellar liquid crystal.

8. A cosmetic composition according to claim 1, wherein the cosmetic composition exhibits a structural color.

9. A cosmetic composition according to claim 1, wherein the nonionic surfactant is a mixture of hydrogenated lecithin and a polyglyceryl fatty acid ester surfactant.

10. A cosmetic composition according to claim 9, wherein the polyglyceryl fatty acid ester surfactant is at least one selected from the group consisting of polyglyceryl-10 caprate, polyglyceryl-10 laurate, polyglyceryl-10 myristate, polyglyceryl-10 trilaurate, polyglyceryl-10 oleate, polyglyceryl-10 dioleate, polyglyceryl-10 stearate, polyglyceryl-10 isostearate, polyglyceryl-10 pentastearate, polyglyceryl-10 behenate, polyglyceryl-10 decalisostearate, and polyglyceryl-10 behenate / elcosadroate.

11. A cosmetic composition according to claim 1, wherein the ultra-long-chain fatty acid is contained in an amount of 0.01 to 5 wt% based on the total weight of the cosmetic composition.

12. A cosmetic composition according to claim 1, wherein the ceramide is contained in an amount of 0.001 to 5 wt% based on the total weight of the cosmetic composition.

13. A cosmetic composition according to claim 1, wherein the cholesterol is contained in an amount of 0.05 to 5 wt% based on the total weight of the cosmetic composition.

14. A cosmetic composition according to claim 1, wherein the nonionic surfactant is contained in an amount of 0.01 to 20 wt% based on the total weight of the cosmetic composition.

15. A method for producing a cosmetic composition having a pearlescent finish comprising the following steps: (1) A step of preparing an oil phase by mixing long-chain fatty acids, ceramides, cholesterol, and nonionic surfactants; (2) A step of preparing a water phase by mixing polyol into purified water; and (3) A step of adding the oil phase to the above-mentioned water phase and mixing it.

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